A liquid delivery device is any device capable of delivering liquid to a specific receptacle. One commonly used liquid delivery device is a pipette. A pipette (also called a pipet, micropipette, pipettor or chemical dropper) is a laboratory instrument used to transport a measured volume of liquid. Pipettes are commonly used in molecular biology as well as medical tests. Pipettes come in several designs, for various purposes having differing levels of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes. Many pipette types work by creating a partial vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense.
Pipettes that dispense between 1 and 1000 μl are termed micropipettes, while standard pipettes dispense a greater volume of liquid. Two types of micropipettes are generally used: air-displacement pipettes and positive-displacement pipettes. In particular, piston-driven air-displacement pipettes are micropipettes which dispense an adjustable volume of liquid from a disposable tip. The pipette body contains a plunger, which provides the suction to pull liquid into the tip when the piston is compressed and released. The maximum displacement of the plunger is set by a dial or electronic interface on the pipette body, allowing the delivery volume to be set. Whereas, for larger volumes, cylindrical pipettes (such as volumetric or graduated pipettes) are used and driven by a pipette aid http://en.wikipedia.org/wiki/Pipette). Most pipettes are made of borosilicate, aluminosilicate or quartz with many types and sizes of glass tubing being available. Each of these compositions has unique properties which will determine suitable applications (http://en.wikipedia.org/wiki/Micropipette). Most micropipettes have a plastic housing for the air displacement works (see reference number 24 in FIG. 1), a fitting post for a disposable plastic tip where the tips may be provided in a variety of sizes and shapes that are designed around specific applications (see reference number 18 in FIG. 1); fluids are drawn into the tips. In most assays tips are discarded after each individual use, usually via an ejector mechanism.
Many common methods in e.g. molecular biology, combinatorial chemistry, forensic science, clinical diagnostics, biochemical assays, etc. use standard manual micropipetters for the transfer of small volumes of fluid to and from various receptacle, including, but not limited to, standard 2 milliliter, 1.5 milliliter, and 0.5 milliliter disposable plastic sample tubes, the standard 96-well microtiter plate format, 384- and 512-well microtiter plates, PCR individual and strip tubes, and analysis devices such as 1D and 2D gels, LC and HPLC micro vials, etc. In each case, the operator handling the micropipette must carefully track the tip of the micropipette in order to deliver the reagent/solution to the correct location and do so without touching any other location which would cause contamination. Many of the materials are clear or translucent as are most solutions and reagents, providing minimal visual cues. Therefore, there is a strong demand in the industry for a practical solution for a researcher to locate the proper well to be filled or sampled.
The instant invention is designed to address the above mentioned problems.